The present invention relates to apparatus for constructing a tunnel, gallery or the like hereinafter collectively referred to as a tunnel.
Various forms of apparatus are known for constructing tunnels underground. One form of apparatus, with which the present invention is mainly concerned, employs a drive or cutting shield composed of elongate members or planks supported in side-by-side relationship around the tunnel so as to contact the wall thereof at least over the roof and side zones. These members are mounted on a rigid frame and are moved, usually by hydraulic rams, to attack a working face. As the tunnel driving progresses the frame is moved up to follow the advanced members. In other constructions the drive shield is in the form of a continuous cylinder advanced by rams rather than separate members.
A major problem frequently encountered with the generally known form of apparatus is that the control or guidance of the drive shield is difficult and there is a tendency for the shield to rotate about its axis. Another problem also encountered is that efficient drainage of water is sometimes difficult to achieve without recourse to pumping equipment which is undesirable in the cramped conditions prevailing.
With regard to the foregoing, a general object of the invention is to provide an improved apparatus for constructing a tunnel.